Neurodevelopmental assessments of young children can be complex and difficult to use by untrained, non-clinical staff in low resourced settings. Additionally, few instruments have been developed or tested for use with culturally diverse samples of children living in poverty. In family homeless shelters in the United States, developmental assessment of the children is especially rare, despite their high risk status. Fifty one percent of homeless children are under age five and a disproportionate number are from African-American or Latino families, and most are exposed to multiple adverse early life experiences. Environmental and family factors (e.g., poverty and racism, maternal depression) adversely impact the developmental trajectories of homeless children. To address these concerns, the Center for Social Innovation (C4) will develop the Vulnerable Child Assessment Tool (VCAT): An Instrument for Use in Resource Limited Settings. Normed on a diverse sample of homeless children ages three to five and based in an ecological framework, the VCAT will make neurodevelopmental assessment accessible to vulnerable children and families in low resource settings. Phases I and II of this study will use a rigorous psychometric approach to develop an ecologically aware instrument with low cognitive burden to measure adverse childhood experiences, risk and protective factors, and developmental delays. During Phase I, a set item pool for each domain will be developed in conjunction with the expert panel and vetted for cognitive burden, cultural responsiveness, and ease of administration. Phase I families will be recruited through Housing Families, a local homeless program serving up to 150 homeless children a day. We will test the pool of items in a small sample of 20 parents and 10 program staff using cognitive interviews and psychometric tests, including Item Response Theory (IRT) and internal consistency reliability. Concurrently, we will develop a prototype online platform and pilot its use for feasibility with the initial items on a sample of 60 children. In Phase II, we wil test the validity and reliability of the instruments using a larger sample of 300 homeless children recruited from programs around the country, and will assess the validity of the instrument by correlating results with gold standard, clinically administered, instruments on a subsample of 50 homeless children. We will further the refine the web based platform, develop a scoring algorithm, and incorporate a recommendations system for service interventions to address identified concerns. This project will build upon on C4's innovative platform used to create the first psychometrically validated instrument to measure trauma-informed care. Using the same back-end technology, the VCAT will enable direct service staff to target limited resources to the most needed areas for intervention at the child, parent, and environmental levels. The instrument will fill a significant gap in the field making valid and reliable assessment of low income; racially diverse children exposed to multiple risk factors more accessible, and serve as a model to develop tools for use with infants or school aged children, and those in other low resourced environments.